Water Quality Treatment

Water Quality Treatment2019-02-06T00:21:54+00:00

Hydrodynamic Separation Systems

(Debris, Gross Solids, Suspended Solids, Sediment, Grease & Oil)

A hydrodynamic separator (HDS) is a flow-through water quality treatment systems that uses fluid dynamics to separate debris and sediment from stormwater runoff. Floatables and neutrally buoyant trash and debris are retained behind a screen, sediment is forced to settle in a sump, and hydrocarbons are retained behind a baffle or with use of absorbents. The Jensen Deflective Separator (JDS), uses cyclonic, vortex separation to concentrate debris in a fashion that prevents blocking the screening device while our Vertical Flow Clarifier (VFC) is specialized for capturing large amounts of hydrocarbons.

Jensen Deflective Separator (JDS)

A Full Capture, Screening, Swirl-Concentrating Stormwater Treatment Unit

The Jensen Deflective Separator (JDS) is a non-blocking, screening, swirl-concentrating, stormwater treatment system with no moving parts to maintain.  Capable of treating flows from 0.7 to 72 cubic feet per second, the JDS retains captured pollutants, even with bypass flows in excess of the treatment design rate.

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JDS Offline Unit

JDS Offline Unit
(click to enlarge)

Resources: Technical Documents, Brochures, Case Studies
Jensen Deflective Separator Installation

JDS Installation

Using the proven continuous deflective treatment process, the JDS captures 100% of trash and debris particles equal to or greater than the screen apertures of either 2400 or 4700-micron (μm).  The treatment process also develops vortex separation, which enables fines to settle through a larger range of flow rates than could be settled in a classic settling tank of the same size.  All JDS units are equipped with an oil baffle, and oil sorbents can be added for enhanced efficiency to permanently remove 80% to 90% of free oil and grease.

The JDS system has a small-footprint, deployed underground in either manholes and/or vaults, which enables greater land-use options than larger, land based water quality treatment systems. JDS units are available in precast manholes as inline or offline units as well as smaller drop-inlet/catch-basin solutions.

The systems are maintained with straight-forward vacuum clean-out efforts from the surface, consistent with standard practices, using readily available vacuum trucks.  Combined, these features make the JDS a cost-effective solution for stormwater treatment in small or large watersheds.

JDS Inline Unit

  1. Stormwater enters the JDS unit from one or more inlet pipes, a grated drop inlet, or a curb inlet.
  2. Incoming water collects in the bay of the inlet trough and passes through the volute entrance to the separation and screening chamber.
  3. In the separation chamber, a spinning vortex captures all floatables and swirl-concentrates solids to the center. The vortex flow produces a washing force across the screen face, preventing it from being blocked, while allowing screened stormwater to pass through the screen and beneath the oil baffle to the outflow.
  4. Swirl-concentrated suspended solids settle and are captured in the sump, which is typically cleaned out by a vactor truck.



Treatment Applications:

  • Stand-Alone Stormwater Treatment Unit (SWTU)
  • Pre-treatment:
    • Detention & Infiltration
    • Bio-Retention & Bio-Infiltration
    • Rainwater Harvesting Cisterns
    • Fine Media, Membrane, & Sand Filters
    • Wetlands, Ponds, & Swales
    • Oil/Water Separators
    • Pump Stations

Efficient Capture & Containment:

  • Non-blocking swirl-concentrating screening unit
  • Total Suspended Solids (TSS), coarse sediment, & sand
  • Full Capture – 100% of trash & debris equal to or greater than the screen aperture
  • 100% floatables control
  • 90% of sediment as small as one third the screen’s aperture
  • Removal of free oil and grease with the use of an oil baffle, and/or optional sorbents
  • Precast inline and offline JDS units treat flows from 0.7 to 73 CFS
  • Cast-In-Place JDS units treat flows from 73 to 273 CFS
New & Retrofit Development Applications:

  • Residential, Commercial, & Industrial
  • Parking Lots & Parking Structures
  • Maintenance Facilities
  • Roads, Streets, Highways & Freeways
  • Intermodal Transportation Facilities
  • Solid Waste Transfer Yards & Landfills

Effective and Convenient:

  • More cost effective treatment per Cubic Feet per Second (CFS) of stormwater processed compared to other structural BMPs.
  • Configured inside typical precast manholes and installed below ground as typical storm drain structures
  • Standard vactor/vacuum truck readily removes all pollutants
  • Maintenance cleanout is achieved from the surface with no confined space entry

Need a hydrodynamic separator specialized for capturing fine sediments and large amounts of grease & oil?

Learn about our Vertical Flow Clarifier (VFC)

Filtration Systems

(Debris, Solids, Suspended Solids, Sediment, Grease & Oil, Nutrients, Metals, Pesticides, Bacteria)

Cartridge Filtration

Advanced Physical and Chemical Treatment

Filter System Flow Rates
Contact Us for Drawings
Drop Inlet Cartridge Filter

Drop Inlet Upflow Filter
(click to enlarge)

Upflow Filters in Manhole Configuration

Upflow Filters in Manhole Configuration
(click to enlarge)

Resources: Guidelines, Brochures, Technical, etc.
Large Upflow Filter

Large Upflow Filter Cartridge in Front of Manhole Base

Jensen Stormwater’s filtration systems incorporate tested and proven 3P Hydrosystem cartridge filters, which provide swirl-concentrating, sedimentation pre-treatment followed by advanced, up-flow filtration in one unit.

Designed for diverse applications, these systems are typically deployed as multi-cartridge systems in precast manhole or vaults structures.

For smaller developments, the filtration systems are deployed in trench vaults, precast drop and curb inlets, or catch basins.

The advanced filtration cartridges use fire-hardened, expanded ceramic spheres engineered to have a very large specific surface area. The media substrate is specially coated with oxides to produce a large cation-exchange capacity (CEC) to target the removal of heavy metals and nutrients.  The result is a filtering media well-suited for severe stormwater treatment applications.

Drop Inlet Filter with Pre-Screening Basket

Debris Basket Being Removed from Above Drop Inlet Filter

Filter media is fine-tuned to address specific pollutants of concern by blending in Granular Activated Carbon (GAC), perlite, zeolite or peat fiber for enhanced bio-filtering.  The media is also equal to, or superior to, granulated activated carbon for addressing the removal of pesticides.

Single-cartridge and multi-cartridge upflow filtration systems work similarly. Upflow Filters in Manhole Illustration

  1. Incoming stormwater enters through one or more inlet pipes.
  2. Swirl-concentration occurs within the separation chamber.
  3. A hole within the shear cone allows solids to settle while preventing scouring during high flows.
  4. The Sump retains settled solids, which are pumped out during maintenance.
  5. Water passes upwards through the filter cartridge media.
  6. An overflow pipe functions as a protective bypass for flows exceeding the design flow.
  7. Filtered water exits the outflow pipe (the outlet for coalesced oil control is not shown for clarity).



Our cartridge filtration systems can be customized for removing the following:

  • Total Suspended Solids (TSS) as well as other fine and course sediments
  • Metals (Al, Cd, Cr, Cu, Fe, Ni, Pb, Zn)
  • Nutrients (phosphorous & nitrogen)
  • Hydrocarbons (grease, oil, etc.)
  • Pesticides
  • Oxygen-demanding substances (biologic and chemical)

Effective Capture, Retention, and Final Treatment:

  • Swirl-Concentrating Component Removes Coarse Sediments, Sand, and Fines
  • Trash/Debris is Retained
  • Removes Oils, Greases, and other Hydrocarbons
  • Captured Pollutants are not Scoured During High-Flow Bypass Conditions
  • Baffled discharge prevents washout of floatables and oil.
  • Achieves Post-Treatment Levels for Offsite Release Directly to Waterways
Deployment Options:

  • Manholes
  • Vaults
  • Drop Inlets, Curb Inlets, & Catch Basins

Advanced Treatment Process:

  1. Physical Filtration: adsorption and absorption  of solids
  2. Cationic Exchange: heavy metals and nutrients
  3. Chemical Precipitation: heavy metals and nutrients
  4. Oil capture and coalescing
New, Retrofit, & Redevelopment Applications:

  • Residential – Single Family, Mixed Use, & High Density
  • Commercial, Industrial
  • Roadways, Parking Lots and Structures, & Airport Taxiways
  • Nurseries and retail garden centers where fertilizers and pesticides are expected
  • Solid Waste Transfer Facilities & Landfills


 Ease of Installation and Maintenance:

  • Plug-and-Play Installation with Precast Components
  • Efficient Upflow Filtration Minimizes Sediment Accumulation on Filters
  • Filters can be Backwashed to Extend Lifespan
  • Convenient Vactor/Vacuum Truck Sediment Cleanout
  • Engineered to Simplify Filter Removal and Replacement

Bacteria and Pollutant Filtration Systems

Antimicrobial Filtration with Zero Toxicity to Receiving Water Biota

Contact Us for Drawings
Fabco Helix in Vault

Cut-Away Showing Helix Filter in Vault
(click to enlarge)

Resources: Guidelines, Brochures, Technical, etc.
Helix Bacterial Filter in Precast Vault

Helix Bacterial Filter in Precast Vault

Jensen Stormwater offers filtration solutions for reducing bacteria in stormwater while also removing debris, sediment, and hydrocarbons.  Our precast manholes and vaults are engineered to deploy the StormSafe™ and Helix ™ filtering systems, each of which utilizes a proven anti-microbial media from Fabco Industries. The bacteria and pathogen killing capacity of these filters is derived from a chemically bound, non-leaching, antimicrobial agent that lasts the lifetime of the media. This antimicrobial filtration is non-toxic, having zero toxicity impact to the receiving water’s biota.

A wide range of design options provides an ability to remove bacteria and pollutants of concern from water quality treatment flows ranging from a few gallons per minute up to 9 Cubic Feet per Second (CFS).

High treatment flows are typically addressed with the Helix filter in a horizontal-flow, vault configuration. Weir configurations ensure that the design water quality flow is completely driven through the microbe-killing foam media. The weir also serves as an overflow bypass system for flows greater than the water quality design flow.

StormSafe Filter Cartridges

StormSafe Bacteria Filtering Cartridges

Moderate to low volume treatment systems are engineered into manholes, curb inlets, and drop inlets beneath the trash grate using either cartridge or Helix filters.

In field tests with the variable conditions and high flow rates that occur in real life applications, the filters removed approximately 70% of total coliform and fecal coliform bacteria, as well as 50% of the enterococci bacteria.

  • The bactericidal agent is permanent and lasts the lifetime of the filter
  • Bacteria are physically destroyed and cannot become resistant
  • Removes and retains trash/debris, coarse sediments, sand, and fines
  • Captured pollutants are not scoured during high-flow bypass conditions


Configuration Options:

Helix Filters in Vault

Helix Filter – Internal View in Precast Vault

StormSafe Filter Cartridges

StormSafe Down-flow Bacteria Filtering Cartridges

  • Down-flow cartridges are ideal for catch basins and smaller vertical treatment applications
    • Filter media options exist for removing other pollutants in addition to bacteria
  • Horizontal tubes with helical-flow media are used in vaults for larger treatment flows
    • Horizontal flow treatment is ideal for low head conditions

View Through Manhole Into Inflow Side of Helix Filter System

View Through Manhole Into Inflow Side of Helix Filter System

Incoming stormwater enters a primary basin where solids settle as sediment, and floatables are retained behind a weir (4).

The pre-treated water passes through debris grating (3) into the horizontal filter columns. A spiral flow path through the filter increases contact, extends filter life, and assures that the entire volume of stormwater contacts the microbe killing foam before it exits the columns and drains from the outflow.

The weir configuration ensures that the treatment design flow is completely driven through the microbe-killing foam filter. The weir also serves as an overflow bypass system for design-exceeding flows.

System Features:Helix Bacterial Filter in Vault

  1. Access manhole
  2. Inflow
  3. Trash/debris separators
  4. Bypass weir
  5. Horizontal filter columns
  6. Outflow



New and Retrofit Development Applications:

  • Recreational areas: coastal & lake beaches
  • Outfalls to stream, creeks and estuaries
  • Parks and parking lots where high levels of bacterial contamination are expected (e.g. dog parks)
  • Roadways
  • Residential – Single Family, Mixed Use, and High Density
  • Commercial Businesses and Restaurants
Flexible Design Options:

  • Vaults
  • Curb Inlet and Drop Inlet Catch Basins
  • Traffic loading, deep-bury, & saturated soil condition designs available
  • Design and configuration options for treating flows from 10-gpm to 9-cfs (4,040-gpm)


Treated Pollutants of Concern (POC):

  • Pathogens
  • Bacterial Load Reduction
  • Total Suspended Solids (TSS) & sediment

Ease of Installation and Maintenance:

  • Convenient Installation with Precast Components
  • Filters can be Backwashed/Cleaned to Extend Lifespan
  • Convenient Vactor/Vacuum Truck Sediment Cleanout
  • Engineered to Simplify Filter Removal and Replacement

Sedimentation Systems

(Suspended Solids, Sediment, Debris, Grease & Oil)

  • StormVault® (SV)
  • Jensen Precast High Velocity Interceptor (JPHV)
  • Sand/Oil Separators
Contact Us for Details or Design Assistance

Total Petroleum Hydrocarbon Removal Systems

(Advanced Oil/Water and Sand/Oil Separation)

  • Jensen Coalescing Media Separator (JCMS)
  • Jensen Coalescing Plate Separator (JCPS)
  • Oil/Water Separator (API design)
Contact Us for Details or Design Assistance
Complimentary Design Assistance?

Jensen Water Resources

Jensen Water Resources is comprised of three specialized teams: Jensen Pump Stations, Jensen Stormwater Systems, and Jensen Advanced Onsite Wastewater Systems.

The Jensen Pump Stations team provides high-quality pump stations for municipal, commercial, industrial, and residential applications. The Jensen Stormwater Solutions team provides products and systems for a diversity of stormwater best management practice applications.
Jensen Advanced Onsite Wastewater Systems creates advanced treatment systems for removing pollutants from wastewater.